Gallup and Lamb are not the same thing as Cooper, Gallup, and Lamb. You can't convince me that you get better by dumping Cooper.
All I'm saying is you have to think years down the road when you have a top ten pick. Outside of Sewell and maybe Rousseau there are no foundational players, so you should go with the best player.
Drafting every position for the defense would be an overreaction, unless the best player happens to be on defense.
Last year's defense wasn't as flawed talent wise as it was very poorly coached.
Three new starters and good coaching would make a huge difference. 2-3 of those starters should come from FA.
We have Gregory, Lawrence, Hill, Gallimore, Anae, and Hamilton up front. Sign one major starter in FA (this alone would be huge). Resign Aldon Smith and maybe resign Woods as a backup.
At LB we have LVE, Smith, and some experiments like Bernard. Grab another FA and resign Thomas as a backup. Jerry won't replace Smith. Sorry but it's not happening. He will continue to be accountable to no one .
We have only Thompson at safety. Sign one clear starter in FA and some depth.
We have Diggs, Brown, both Robinsons, and Canady at CB. Sign two FAs and maybe Goodwin for depth. Draft one if you think Robinson was a bust.
Draft at 2 or maybe 3 defenders from the first 4 rounds. That's a fine enough roster, Jaylon aside.
You won't be great on defense but you won't be bad, either.